Thats a huge jump in code years, I guess they just wanted to rip the bandaid off and get it over with. Pennsylvania is still on the 2002 addendum to the 2000 code.

I hadn't heard of interlocks on car doors yet. I know the two big ones are special 3d light curtain will be mandatory and the video/text/phone system. But your also getting all the stuff that changed in the 10,13, and 16 codes. Phone line monitoring also. If yall install residential elevators the hoistway doors will have to essentially be flush and requires new car gates with special hard hinges. Your fire service phase two switch and buttons have to be behind a panel now. Lots of changes over the years. 10 foot candles of light anywhere on cartop. I'm forgetting a ton right now.

Pm me, I'll email you that book in a pdf..